Combination-digester.



A. P. RICHTER.

COMBINATION DIGESTEB.

APPLIGATION FILED APR. 4, 1910.

1,031,088. Patented July 2, 1912.

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COMBINATION DIGESTER.

APPLICATION FILED APR. 4, 1910.

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COLUMBIA PLANOGRAPH 20., WASHINGTON, n c.

A. P. RICHTER. COMBINATION DIGESTBR.

APPLICATION FILED APR. 4, 1910.

1,031,088. 7 Patented July 2,1912.

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AUGUST FREDERICK RICHTER,

0F WATERTOWN, NEW YORK.

COMBINATION-DIGESTER.

Specification of Letters Patent.

Patented July 2, 1912.

Application filed April 4, 1910. Serial No. 553,211.

To all whom it may concern:

Be it known that I, AUGUST F. RICHTER, a citizen of the United States,residing at lVatertown, in the county of Jefferson and State of NewYork, have invented a new and useful CombinationDigester, of which thefollowing is a spjecification.

This invention relates to what may be termed a combination digester foruse in the production of fiber intended to be used in the manufacture ofpaper.

The object of the invention is to provide a digester which can be usedin the chemical process of producing fiber from chips and the like andin which a relatively weak solution may be used in order to produce ahigh quality of fiber.

A further object of the invention is to provide a digester which isadapted to treat the contents thereof with the maximum of efficiency andthe minimum of time.

WVith the foregoing and other objects in view which will appear as thedescription proceeds, the invention resides in the combination andarrangement of parts and in the details of construction hereinafterdescribed and claimed it being understood that changes in the preciseembodiments of invention may be made within the scope of the claimswithout departing from the spirit of the invention.

In the accompanying drawings forming part of this specification, Figure1 is a vertical section through a combination digester constructed inaccordance with the present invention, said digester being partly brokenaway; Fig. 2 is a transverse section through the digester shown in Fig.1 on a line above the steam supply pipe; Fig. 3 is a transverse orhorizontal section similar to Fig. 2 taken on a line through the steampipe; and Fig. 4.. is a view similar to Fig. 1 showing the lower portionof a slightly modified form of the digester.

Like reference numerals indicate corresponding parts in the differentfigures of the drawings.

The device of the present invention, briefly outlined, comprises adigester formed with a suitable lining and having adjacent the lowerportion thereof a suitable steam jacket, surrounding the portions of thedigester which are unlined, said steam jacket being in communicationwith a plurality of supported in any suitable manner prefer ably invertical position, by means such as the uprights l, and consistspreferably of an upper portion or dome indicated generally by thereference letter A, a lower portion or cone indicated generally by thereference letter B, a mouth C by means of,

which the chips or other material are fed to the digester, and a lowerend or blow-out in dicated generally by the letter D, by means of whichthe contents of the digester are removed at proper times.

The digester proper consists preferably of an inner shell 1 and an outershell 2 forming between them a suitable steam jacket or chamber 3. Theouter shell 2 of the steam chamber 3 may extend upward to any de sireddistance short of the lower portion of the dome A; that is to say it isunnecessary to extend the steam jacket any higher than the approximatelower portion of the dome A. For example, in the preferred form shown inFig. 1 the steam jacket extends to the base of the dome A, whereas inthe modified structure illustrated in Fig. 4: the jacket extends merelyto the upper end of the cone. The lining 4 preferably consists of aplurality of layers of acid proof tile laid in an intermediate acidproof composition of any suitable character. The lining l preferablystarts approximately at the point where the steam jacketterminates and,

extends from that point on up to the top of the digester. It is found inpractice that by thus arranging the steam jacket and the inner lining,neither one interferes with the action, strength or etliciency of theother. That is to say the lining does not interfere with the steamjacket and the steam jacket does not prevent the lining from beingsecurely held in place adjacent the dome of the digester where it ischiefly needed.

In order to prevent the acid liquor from 7 working its way in betweenthe lining and the steel shell of the digester, a ring 5 of bronze orother suitable material is secured to the inner shell of the digester atthe point where the lining begins. The ring 5 thus serves the two-foldpurpose of supporting the lining t and of preventing the acid liquorfrom working its way in between the lining and the shell so as to injurethe latter.

Steam is supplied to the jacket 3 through a suitable steam inlet pipe 6.From the jacket3 the steam passes through a plurality of pipes 7 to aplurality of manifolds 8 with which are connected steam heating pipes'9. The different heating pipes 9 in each set thereof, are connectedwith each other at their upper ends by a plurality of manifolds 10, eachof which is connected by means such as the pipe 11 with a circular steampipe 12 having at one point therein an outwardly extending vent pipe 13provided with a valve 14. The different sets of steam heating pipes 9are suitably secured in place by means such as the brackets or clamps15. It will be noted that the pipes 7 connected with the manifolds 8, inthe embodiment of invention shown extend into the jacket 3.

In operation, the digester is charged with chips or other material to beconverted into pulp, together with the cooking liquor.

Steam is immediately admitted at the pipe 6 and maintained at a lowpressure, say forty pounds. As soon as the digester has been filled andthe cover plate secured at the top 0, the steam pressure within thejacketed cone is raised rapidly to the desired pressure, generally 85 to100 pounds, and the vent 13 at the top of the circulating coil is openedsufiiciently to permit the escape of any accumulation of air which mayhave become trapped. The heat radiation is very rapid throughout theentire digester by reason of the greatly increased area of heatingsurface opposed to the liquor due to this style of construction and atemperature equal to boiling point is soon reached, at which time thesteam inlet valve is regulated to accord with the conditions, or thecooking time desired. The condensation formed within the coils falls bygravity into the bottom and then into the cone acket, from which it isdrawn by means of the pipe 20 provided with a valve 21. A suitable steamtrap (not shown) may be used.

The action of the steam in the external steam jacket, causes a coatingto form on the unlined section of the cone, and this coating protectsthe same from the corrosive action of the acid liquor. This coating,however, is not allowed .t0, accumulate to a thickness or extent whereit will retard the proper action of the heat within the steam jacketupon the contents of the digester.

The digester .of' the present invention is formed with a large amount ofheating surface bymeans of which rapid cooking is produced and acorrespondingly greater capacity for a stated size of digester ispossible. Moreover'a' better quality of pulp is obtained by reason ofthe fact that the steam or heating medium is kept out of contact withthe acid liquor or pulp, so that the water of condensation cannot dilutethe acid liquor so as to render it necessary to employ a strong acidliquor in order to counteract the effect of the water of condensation.That being the case, it is possible to employ a relatively weaker acidliquor, for which reason a high grade of pulp is secured.

The device of the present invention is not to be limited to anyparticular process. It can be used with either the sulfite process orthe soda and sulfate process of producing pulp. Moreover it can be usedin other lines of manufacture and in other industries.

What is claimed as new is l. A partially lined and partially jacketeddigester, the lining terminating approximately at the upper end of thejacket, and internal heating means in said digester.

2. A digester comprising a shell having at one portion thereof an innerlining and at another portion thereof an outer jacket, the liningterminating approximately where the lining begins, and internal heatingmeans in said digester.

3. A digester having a jacketed cone and a plurality of internallydisposed heating devices located around the central portion of thedigester, and away from the lower end thereof, said jacket and heatingde vices being in communication with each other.

t. A digester having a dome provided with a lining, a steam jacketlocated below the dome, a plurality of internally disposed heatingdevices connected with said jacket, and means for supplying steam tosaid jacket-s and pipes.

5. A digester having a lined dome and a jacketed cone, the liningterminating at the upper end of the jacketed cone, and intermediatelydisposed internal heating devices.

6. A digester having a lined dome, a j acketed cone and intermediatelydisposed internal steam pipes.

7. A digester having a lined dome, a jacketed cone, and intermediatelydisposed internal heating devices.

8. A digester having a dome formed with a lining, a cone at the lowerend thereof formed with a steam jacket, a plurality of steam pipeslocated inside of said digester intermediate the dome and the cone, andconnections between the said pipes and said steam jacket.

9. A digester having a dome formed with a lining, a cone at the lowerend of said digester, a steam jacket around said cone, means forsupplying steam'to said jacket, a plurality of manifolds incommunication with said jackets, pipes connected with said manifolds andextending upwardly, a second set of manifolds connected with the upperends of said pipes, a circular distribas my own, I have hereto aflixedmy signauting pipe connected with each of said ture in the presence oftWo Witnesses. second set of manifolds, a vent pipe connected With saiddistributing pipe, and AUGUST FREDERICK m means for Withdrawing Water ofcondensa- Witnesses: tion from the said jacket. R. O. YOUNG,

In testimony that I claim the foregoing E. J. DAULTON.

Copies of this patent may be obtained for five cents each. by addressingthe Commissioner of Patents, Washington, D. G.

